1. Field of the Invention
The present invention relates to a cooling system for cooling a hot object such as a communication apparatus contained in a closed container.
2. Description of Related Art
An electronic apparatus used in a base terminal in a telecommunication system is usually contained in a closed container. Such apparatus generates considerable heat in the closed container, and such heat has to be dissipated to protect the apparatus. For this purpose, two devices are generally used: one is a conventional air-conditioner installed in the container, and the other is a heat exchanger which exchanges inside heat with outside air.
An example of such heat exchanger is shown in FIG. 11. A heat pipe 100 is contained in a casing 130. The casing 130 is divided into a hot chamber 150 and a cool chamber 160 by a separating wall 140. The heat pipe 100 having an evaporator 101 and a condenser 102 is installed through the separating wall 140. The evaporator 101 is located in the hot chamber 150 while the condenser 102 is located in the cool chamber 160. Air heated by a hot object flows into the hot chamber 150 and is cooled down by the evaporator 101. Then, the cooled air flows out from an outlet by operation of a blower 110. Heat exchanging medium evaporated in the evaporator 101 flows into the condenser 102. The medium is cooled down in the condenser 102 by outside air introduced into the cool chamber 160. Outside air flows through the condenser 102 and is exhausted to the outside again by operation of a blower 120. Another example of such heat exchanger is shown in FIG. 12. A heat exchanger 200 is contained in a casing 230 which has two blowers 210, 220. Heat is exchanged between heated air and the outside air, and cooled air is sent through an outlet by operation of the blower 210.
When a conventional air-conditioner is used as a cooling device for cooling the closed container, a running cost for operating the air-conditioner is high, because the air-conditioned is generally operated to maintain temperature constant in a heat-insulated container. In other words, the air-conditioner has to be operated even when outside temperature is low as in winter time.
On the other hand, when such a heat exchanger as exemplified above is used as a cooling device, efficiency of heat exchange is not high, because the heat exchanger is made as a unit, and therefore, the evaporator portion cannot be positioned at an optimum place to exchange heat efficiently. Moreover, temperature in the container varies according to the outside temperature.